A solid-state image pickup device includes an imaging region in which a plurality of pixels respectively including photodiodes are arranged two dimensionally. Further, in some cases, the solid-state image pickup device includes an A/D converting circuit that outputs a digital value according to an amount of electric charge generated in a photodiode of each pixel. In such a solid-state image pickup device, the number of pixels is ever-increasing, and further, the speeding-up of imaging has been demanded. Such an increase in the number of pixels and speeding-up of imaging generally bring about an increase in power consumption of the solid-state image pickup device.
Patent Document 1: Japanese Translation of International Application Kohyo) No. 2002-505002